Abstract

Oxide dispersed strengthened (ODS) steel is an important candidate for Gen-IV reactors. Oxide embedded in Fe can help to trap irradiation defects and enhances the strength of steel. It was observed in this study that the size of oxide has a profound impact on the depinning mechanism. For smaller sizes, the oxide acts as a void; thus, letting the dislocation bypass without any shear. On the other hand, oxides larger than 2 nm generate new dislocation segments around themselves. The depinning is similar to that of Orowan mechanism and the strengthening effect is likely to be greater for larger oxides. It was found that higher shear deformation rates produce more fine-tuned stress-strain curve. Both molecular dynamics (MD) simulations and BKS (Bacon-Knocks-Scattergood) model display similar characteristics whereby establishing an inverse relation between the depinning stress and the obstacle distance. It was found that (110) oxide || (111) Fe (oriented oxide) also had similar characteristics as that of (100) oxide || (111) Fe but resulted in an increased depinning stress thereby providing greater resistance to dislocation bypass. Our simulation results concluded that critical depinning stress depends significantly on the size and orientation of the oxide.

Department(s)

Civil, Architectural and Environmental Engineering

Second Department

Mechanical and Aerospace Engineering

Publication Status

Open Access

Comments

National Natural Science Foundation of China, Grant 11505037

Keywords and Phrases

Dislocation dynamics; Edge dislocation; Molecular dynamics (MD) simulation; Orowan loop; Oxide dispersed strengthened (ODS) steel

International Standard Serial Number (ISSN)

2234-358X; 1738-5733

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 Elsevier, All rights reserved.

Publication Date

01 Feb 2020

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